1. Technical Field
The present invention relates to a low-power wireless charging apparatus and a method thereof.
2. Description of the Related Art
In general, the majority of wireless communication devices require charging; however, the recently launched mobile devices have different types of wired connectors.
In order to overcome user inconvenience of charging mobile devices in a wired manner, a wireless charging technique has quickly progressed.
The wireless charging technique is performed using a magnetic resonance scheme and a magnetic induction scheme.
In particular, the magnetic resonance scheme allows for configuration of a system that can be charged at a distance, but since it is transferrable to a human body or a different device, harmfulness thereof remains to be solved in the future.
Meanwhile, the magnetic induction scheme is a power transmission scheme using electromotive force induced from a magnetic field. Since the magnetic induction scheme can transmit power only within a short distance of a few millimeters or a few centimeters, it is considered not to be harmful to the human body in comparison to the power transmission scheme using magnetic resonance.
For this reason, development of the wireless charging technique employing the magnetic induction scheme and propagation of corresponding products have been quickly promoted.
In a related art wireless charging apparatus and method using the magnetic induction scheme, it is determined whether or not there is a receiver desired to be wirelessly charged and, when a receiver to be wirelessly charged is detected, the receiver is authenticated whether or not it is a predefined one, and then, a wireless power signal is generated and transmitted to the receiver so that the receiver can be charged with power as much as required.
Namely, in the related art wireless charging apparatus and method, wireless power is charged in the receiver in order of detecting the receiver, authenticating the receiver, generating wireless power, and transmitting the wireless power to the receiver, and all of these processes are performed by a single control unit (e.g., a main control unit).
In particular, in order to detect the receiver, the controller must periodically and continuously transmit a receiver detection signal at certain time intervals, and when the wireless charging apparatus can simultaneously charge a plurality of receivers, the wireless charging apparatus commonly uses a method of continuously transmitting a detection signal at certain time intervals in order to detect receivers and detecting an impedance variation reflected from a resonator (or coil) by a voltage or a current sensor.
Thus, the related art wireless charging apparatus and method consume much power in detecting receiver(s).